In grocery stores, it is very important to carry as much product as possible in as small an area as possible. The product also must be apparent to the consumer and attractively displayed.
One way to increase product density is to place the product on shelving with only a minimal amount of space between the top of the product and the bottom of the next higher shelf. This presents difficulties with respect to the visual appeal, as well as in stocking the shelves. When restocking a shelf, the older product needs to be positioned at the front of the shelf. This is particularly an issue with perishable products, such as dairy products such as yogurt, and the like. The limited space between shelves makes it difficult for the store employees to restock the product.
There are shelving units that are supported on either side by rollers that allow the shelves to slide outwardly for restocking. This arrangement is not optimal for refrigerated display cases that support dairy products. Further, it is always desirable to minimize costs.